Howaed caee



Witnewaws (No Model.)

' H. CARR.

' PROJEUTILE.

No. 245,994. Patented Aug. 23,1881.

In v'a 11170 1 q 7- v v 7d u. PETERS. PhotwI-iliwyupiwr. Wahinghm v.1:

UNITED STATES PATENT OFFICE.

HOWARD CARE, OF SAN FRANCISCO, CALIFORNIA.

PROJECTILE.

SPECIFICATION forming partof Letters Patent No. 245,994, dated August23, 1881,

Application filed November 26, 1880. (No model.)

To all whom it may concern:

e it known that I, HOWARD CARR, ot' the,

city and county of San Francisco, State of California, have invented anImproved Projectile; and 1 do hereby declare the following to be a full,clear, and exact description thereof.

My invention relates to certain improvements in projectiles for guns;and it consists in a novel formation of a projectile having thecannelures or'grooves formed around its base in spiral lines, whichextend to a point near the center of the bullet, where they disappearina rib on the rear part of the smooth portion of the bullet, which smoothportion continues from that point to the apex.

The object of this invention is to provide an opening or openings aroundthe base of the bullet, by which the pressure of the gas will be exertedtoward the axis around the rear portion of the bullet when the explosionof the powder charge takes place, and thus prevent such an upsetting ofthe bullet as to cause too great friction within the barrel of the gun.It also serves to distribute the lubricant thoroughly over the spaceoccupied by the cannelures or grooves upon the bullet and within thebarrel.

Referring to the accompanying drawings for a more complete explanationof my invention, Figure 1 is a view of my projectile. Fig. 2 is the endview in the barrel of the rifle. Fig. 3 is a view of a bullet. Fig. 4 isa longitudinal section of a rifle with the bullet.

A is the front portion of my projectile, which may have anysuitably-shaped point, this not being any part of my invention.

In the ordinary construction of bullets the cannelures encircle thebullet from the base to a point in its length determined by theparticular pattern of the ball, but usually near its center of length,in the form of alternate rings and depressions, the rings having such anelevation as to be forced into the grooves of the rifle, and thus havesuch a bearing upon the lands that the propulsion of the bullet throughthe barrel will give it the required rotation upon its axis to steadyits flight. The grooves or depressions on the ball are made deep enoughto hold the necessary quantity of lubricant to prevent too much frictionand the leadingof the barrel. In this form of bullet the base forms thefirst rim of the cannelures, and receives the full impact ofthe chargewithin the gun, thus upsetting the bullet and forcing it into thegrooves of the rifle. The amount of this upsetting depends upon thesoftness or hardness of the metal of which the bullet is composed addthe quantity of the powder used; but it is liable to vary with the bestprecautions, and the friction of the bullet through the barrel will thusvary its flight.

In my invention 1 form the cannelures B in spirals or screw-threads, oftwo, three, or more to the inch, these spirals beginning at a ring orcylindrical base, 0,0f the smooth front portion, A,-of the bullet, andextending around the rear portion until they reach the base, where itwill be seen, as in Fig. 2, that each groove between the raised portionof the cannelures opens into the powder-chamber behind the bullet, whilethe raised portions of the cannelures cross the rifling of the gun at anangle and fit into it, so that the bullet will be rotated upon its axisas it leaves the gun.

By this construction it will be seen that each of the grooves of thecannelures forms a continuous passage around the bullet from its base tothe ring 0, and when the explosion of the powder charge takes placewithin the gun the pressure of the gas upon the lubricant which fillsthe grooves, or the pressure of the gas itself, if there is nolubricant, will extend along these passages, so as to act upon the ring0 (which fits the gun snugly) and impel the bullet forward from. thatpoint, as well as from its base, and will also exert a centripetalpressure upon the bullet, thus relieving the sudden forward force of theexplosion, and dividing it so that it does not act entirely upon thebase, and the bullet will therefore be so much upset. The spiral ringsand grooves forma screw of short pitch, but having the same directionwith thegrooves of the rifle, and, while the pitch is too short toinfluence the rotation of the bullet, the cannelures are continuous, andwhen in motion there will be less resistance to the forward motion thanwhen the cannelures are plain rings. This gives the bullet a lowertrajectory than fit the barrel tightly and. prevent the escape of gas,whereby the force of the explosion is di- 15 vided between the base ofthe projectile and the ring 0, and also exerts a pressure toward theaxis, substantially as herein described.

In witness whereof I have hereunto set my.

hand. 20

HOWARD C ARR.

WVitnesses:

GEO. H STRONG, J. H. BLOOD.

